A semiconductor light emitting device, generating light of various colors through electron-hole recombination, has many advantages, such as a relatively long lifespan, a low degree of power consumption, and the like. Thus, demand for semiconductor light emitting devices continues to rise. However, in a semiconductor light emitting device, when a semiconductor layer is grown, strain may be generated due to a difference in lattice constants and coefficients of thermal expansion between the semiconductor layer and a substrate, resulting in the generation of lattice defects.
Also, a difference in refractive indices between the semiconductor layer and an external material causes a considerable portion of light to be totally internally reflected, degrading light extraction efficiency. Thus, in the art, a method of improving a lattice defect and luminance efficiency of a semiconductor light emitting device is increasingly required.